Peterborough's former MP - who described his party's manifesto as "electoral poison" after losing his seat - has been appointed the Brexit Secretary's chief of staff.
Stewart Jackson, a prominent Leave campaigner, said he was "hugely honoured" to take up the post at a "historic juncture".
He lost the Peterborough seat he had held for 12 years in the June general election and pinned the blame on Theresa May's manifesto.
In the days following he described it as "shockingly bad ...lacking passion, it was bland, it lacked vision ... above everything else a real lost opportunity".
He later openly criticised Mrs May for not contacting him directly after he lost his seat.
Mr Jackson confirmed his new job as special adviser (SpAd) and chief of staff at the Department for Exiting the European Union in a message on Twitter.